The functionality I am after should allow to link any nodes on the canvas by setting the Source and the Target attributes of a corresponding Link to the names of the source and target nodes, without making the nodes aware of the fact that they may have been linked.

This seems to be a simple feature that GMF should allow out of the box, but I seem not being able to build my gmf model, which would support it.

Specifically, while using the dashboard to combine the graphical and tooling definition, the links are absent from the available items in the wizard dialog (attachment Linksabsent.png):

However, I have defined them in both graphical (attachment gmfgraph.png):

and tooling (attachment gmftool.png):

If, on the other hand, I will manually add the link to the gmf mapping definition, the Containment feature drop down does not list the Link model either (attachment manuallink.png):

and proceeding without it makes the mapping invalid.

I would appreciate any pointers and hints on how to set up these generic links.

Properties 'domainMetaElement' (UI: Element) and 'sourceMetaFeature' (UI: Source Feature) should not be specified. Property 'linkMetaFeature' is an EReference; EClass that contains it is a link source and EReference type is a link target.

However this statement: Property 'linkMetaFeature' is an EReference; EClass that contains it is a link source and EReference type is a link target. needs further clarification/decoding.

Can anybody kindly explain what it means, so that it could understood outside of the GMF context? What are practical steps to achieve this?

The page above also talkes about referencing "model facets":

TypeLinkModelFacet - for type based links
FeatureLinkModelFacet - for feature based links

Which seem to introduce the notion of "Feature based links" -- is it the same as the "Reference based links", or is it a third type of links?